apply css class conditionally react code example

Example 1: conditional style react

class App extends Component {
  constructor() {
    super()
    this.state = { isRed: true }
  }

  render() {
    const isRed = this.state.isRed

    return <p style={{ color: isRed ? 'red' : 'blue' }}>Example Text</p>
  }
}

Example 2: conditional classname prop react

<span className={todo.completed ? "true" : ""}>